Browsing by Author "Izadian, Afshin"

Now showing 1 - 10 of 59
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    Abandoned Mine Voids for Pumped Storage Hydro
    (Juniper Publishers, 2019) Schubert, Peter J.; Izadian, Afshin; Wheeler, J. W.; Electrical and Computer Engineering, School of Engineering and Technology
    Pumped Storage Hydro (PSH) is geographically limited but can expand greatly if abandoned subsurface coal mines are leveraged for the lower reservoir. Such lands are already permitted, generally less desirable, and found in regions eager for job creation. Vertical stacking of the upper and lower reservoirs is an efficient use of the land. Water can be raised by electric pumps as part of energy arbitrage; however, water can also be raised with Hydraulic Wind Turbines. HWTs are far less costly than traditional electric turbines, and start-up at lower wind speeds - thereby extending their geographic range. The HWT masts can serve double duty as tent poles to support translucent architectural fabric over the surface lake. This prevents evaporation and ingress of wildlife, and provides an interior space useful for non-electric revenue, such as aquaculture and greenhouses. Water cycled through the system can, in some cases, supplement local sources. Seepage through water tables replenishes clean water. Subsurface water is cool and can be circulated through server farms in data centers which represents a potential revenue source that can be started up well in advance of the primary energy storage operation. Combined, these factors bring an innovative solution to site selection, design, and engineering for PSH which promises accelerated commissioning and permitting, and low-cost operation. The bottom line for communities in Coal Country is more jobs and cheaper power.
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    Adaptive Nonlinear Model-Based Fault Diagnosis of Li-ion Batteries
    (IEEE, 2015-02) Sidhu, Amardeep Singh; Izadian, Afshin; Anwar, Sohel; Department of Mechanical Engineering, School of Engineering
    In this paper, an adaptive fault diagnosis technique is used in Li-ion batteries. The diagnosis process consists of multiple nonlinear models representing signature faults, such as overcharge and overdischarge, causing significant model parameter variation. The impedance spectroscopy of a Li-ion LiFePO4 cell is used, along with the equivalent circuit methodology, to construct nonlinear battery signature-fault models. Extended Kalman filters are utilized to estimate the terminal voltage of each model and to generate residual signals. The residual signals are used in the multiple-model adaptive estimation technique to generate probabilities that determine the signature faults. It can be seen that, by using this method, signature faults can be detected accurately, thus providing an effective way of diagnosing Li-ion battery failure.
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    Analysis of a hydrostatic drive wind turbine for improved annual energy production
    (AIMS Press, 2018-10-21) Deldar, Majid; Izadian, Afshin; Anwar, Sohel; Department of Mechanical and Energy Engineering, School of Engineering and Technology
    This paper presents an analysis on ways to improve the annual energy production (AEP) of a wind turbine utilizing a drivetrain that operates based on the hydrostatic transmission. The system configuration of such a drivetrain is explained in details and a comparison of operation and characteristics with existing drivetrains is provided. AEP was estimated for these configurations through appropriate dynamic modeling and operational efficiency optimization. Optimal selection of a number of design variables and system parameters contributed to the improvements in the AEP. Findings of this study demonstrate that the proposed hydrostatic drivetrain improves the AEP of a 750 kW turbine by up to +8% when compared with a geared wind turbine. The AEP improvements of the hydrostatic drive wind turbine were more than 10% for a 1.5 MW system over geared configuration. It is also demonstrated that the efficiency of power generation can be improved under various wind speeds. The suitable selection of synchronous speed of the generator directly improves the efficiency of operation by up to 35% at low wind speeds. An efficiency improvement was also observed under higher operating pressures and longer turbine blades.
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    Analysis of a hydrostatic drive wind turbine for improved annual energy production
    (AIMS, 2018) Deldar, Majid; Izadian, Afshin; Anwar, Sohel; Mechanical Engineering and Energy, School of Engineering and Technology
    This paper presents an analysis on ways to improve the annual energy production (AEP) of a wind turbine utilizing a drivetrain that operates based on the hydrostatic transmission. The system configuration of such a drivetrain is explained in details and a comparison of operation and characteristics with existing drivetrains is provided. AEP was estimated for these configurations through appropriate dynamic modeling and operational efficiency optimization. Optimal selection of a number of design variables and system parameters contributed to the improvements in the AEP. Findings of this study demonstrate that the proposed hydrostatic drivetrain improves the AEP of a 750 kW turbine by up to +8% when compared with a geared wind turbine. The AEP improvements of the hydrostatic drive wind turbine were more than 10% for a 1.5 MW system over geared configuration. It is also demonstrated that the efficiency of power generation can be improved under various wind speeds. The suitable selection of synchronous speed of the generator directly improves the efficiency of operation by up to 35% at low wind speeds. An efficiency improvement was also observed under higher operating pressures and longer turbine blades.
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    Application of Adaptive Estimation Techniques on Battery Fault Diagnosis
    (Office of the Vice Chancellor for Research, 2013-04-05) Singh, Amardeep; Izadian, Afshin; Anwar, Sohel
    High energy storage systems like Li-ion Batteries are one of the most widely used renewable energy sources today. They find applications in everyday electronic gadgetry, critical medical devices, hybrid & electric vehicles to name a few. Our study aims to observe continuously the state of the Li-ion battery and detect Over Charge (OC) and Over Discharge (OD) failures occurring in real time. Both conditions are detrimental to the health of the battery, while over charge can lead to overheating and thus vaporization of active material and hence explosion, over discharge can short the battery cell. However, these types of failures can be detected before they occur and by raising a flag before the system reaches the failure condition such failure modes can be avoided. Different battery models based on equivalent circuit approach are constructed using the impedance spectroscopy data from Li-ion battery cells. Kalman filters are used to estimate the state of each system and subsequent residuals are generated for each model. Multiple model adaptive estimation is then used, where the generated residuals are evaluated and the fault probabilities are generated. Based on these probabilities, the system is classified as normal operation, OC fault or OD fault. Simulation results show that the battery faults can be detected and diagnosed in real time, thereby proving to an effective way of Li-ion battery fault diagnosis.
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    A Bipolar SEPIC Converter with Wide Output Voltage Range
    (Office of the Vice Chancellor for Research, 2015-04-17) Liu, Kaiyang; Izadian, Afshin
    Energy Systems and Power Electronics Laboratory, Purdue School of Engineering, IUPUI. In order to pursue a perfect inverter, a new inverter technology is designed based on SEPIC converter that can efficiently generate pure sinusoidal waveforms and operate in a wide range of loading conditions. The groundbreaking design of the new inverter is that, for the first time, the number of high-frequency switching-transistors is reduced to one. By changing the switching frequency and duty cycle for the switch, the voltage-level of the output signal will be continuously controlled to produce a nearly pure sinusoidal waveform, and the voltage-level can reach infinity without using any switch map in theory. In order to achieve the DC to AC conversion, inversing the polarity and the boost operation for the output voltage are the two main problems in the process of achieving this goal. To proof the possibility of the new inverter technology, a research for a bipolar SEPIC converter is firstly proposed in order to achieve the voltage polarity inversion and the boost operation. The research basically use a diode to regulate the current direction that goes through the load. By changing the direction of the diode, the polarity of the output voltage can be inversed. For the boost operation, a simulation setup in Simulink and some actual tests have been used to find out the sizes for each elements in the circuit that can boost the output voltage of the converter to 110V at a specific frequency and duty cycle of the only switch. The result of the research had showed that this converter not only had the capability to provide a very wide output voltage ranges and power levels, but also can generate output voltage and power levels for positive and negative polarities.
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    Combined Generation and Optimization of a Wind-Solar-Battery Power System
    (Office of the Vice Chancellor for Research, 2014-04-11) Shen, Dan; Izadian, Afshin
    Compared with other renewables, wind and solar have been established as proven future sources of energy, because of their environment-friendly, safe and cost-effective characteristics. However, there are some difficulties associated with combined utilization of solar and wind, e.g. intermittency of wind and of the solar radiation, and their variation do not match the time distribution of the demand. For this purpose, advanced network of multiple renewable energy systems with storage units have been proposed. Small-scale standalone combination of solar, wind and battery has been found effective in some independent power supply system. Proposed in this research on a standalone distributed hybrid power system which consists of solar power, wind power and battery storage. A control strategy is introduced to maximize the simultaneous energy harvesting from both renewable sources. The supervisory controller results in five contingencies considering the level of power generation available at each renewable energy source and the state of charge in the battery. Power converters interface the source with a common DC bus. The interfacing converter is controlled either as a current or a voltage source. A supervisory controller is proposed to accomplish the source type allocations and balance of energy in the operating contingencies. Simulation results demonstrate accurate operation of the controllers and functionality of the maximum power point tracking algorithm in each operating condition both for solar and for wind power.
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    Configuration Analysis and Design of a Wind Turbine With Hydrostatic Transmission System
    (ASME, 2016-11) Deldar, Majid; Izadian, Afshin; Anwar, Sohel; Mechanical Engineering, School of Engineering and Technology
    This paper presents a methodology for designing and dimensioning of hydrostatic transmission system (HTS) configurations for wind turbines. HTS provides an alternative method to the gearbox in wind power applications. It decouples the turbine and the generator such that the generator can be driven at synchronous speed regardless of wind speed variation. A comparison of different HTS configurations shows that the functionality and performance of the proposed system depends on proper dimensioning of hydraulic components and the circuit configuration. Practical constraints of wind turbine and hydraulic technologies are considered in the design to configure an industrial scale system. The design objectives include obtaining the maximum system efficiency at the rated and high efficiency at partial load. Different hydrostatic systems were designed and simulated to show potentials for improving the overall efficiency of wind power using HTS. It was shown that the larger swept area and moderate speed generator improve efficiency of hydrostatic drivetrain. Optimization of the entire HTSWT can improve output power from a HTSWT to an extent that its annual energy production (AEP) becomes closely equal to AEP of a geared WT.
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    Control of a Hydraulic Wind Power Transfer System under Disturbances
    (IEEE, 2015-10) Vaezi, Masoud; Izadian, Afshin; Department of Engineering Technology, IU School of Engineering and Technology
    Hydraulic wind power transfer systems deliver the captured energy by the blades to the generators differently and through an intermediate medium i.e. hydraulic fluid. This paper develops a control system for a nonlinear model of hydraulic wind power transfer systems. To maintain a fixed frequency electrical voltage by the system, the generator should remain at a constant rotational speed. The fluctuating wind speed from the upstream applies considerable disturbances on the system. A controller is designed and implemented to regulate the flow in the proportional valve and as a consequence the generator maintains its constant speed compensating for low wind speed and high wind speed disturbances. The controller is applied to the system by utilizing MATLAB/Simulink.
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    Control of a Hydraulic Wind Power Transfer System under Wind Disturbance
    (Office of the Vice Chancellor for Research, 2014-04-11) Vaezi, Masoud; Izadian, Afshin
    The energy of wind can be transferred to the generator by employing a gearbox or through an intermediate medium such as hydraulic fluids. In this method, a high-pressure hydraulic system is utilized to transfer the energy produced from a wind turbine to a central generator. The speed control of wind driven hydraulic machinery is challenging, since the intermittent nature of wind imposes the fluctuation on the wind power generation and consequently varies the frequency of voltage. On the other hand, as the load of the generators increases, the frequency of the voltage drops. Therefore, hydraulically connected wind turbine and generator need to be controlled to maintain the frequency and compensate for the power demands. This poster introduces a closed loop control technique to maintain a constant frequency at the wind turbine generator. The governing equations of the renewable energy transfer system are derived and used to design the control system. The speed control profile obtained from a PI controller demonstrates a high performance speed regulation. The simulation results demonstrate the effectiveness of both the proposed model and the control technique.